KR100826850B1 - Fluorescent lamp and method of fabricating the same - Google Patents

Abstract

A fluorescent lamp and a method of manufacturing the same are provided. Fluorescent lamp according to the invention, the glass tube; And external electrodes formed at both ends of the outer circumferential surface of the glass tube, wherein the glass tube has a length of the effective electrode portion inside the external electrode at one end of the glass tube equal to the length of the effective electrode portion at the other end of the glass tube. It is done. According to the present invention, one end of the glass tube is molded such that the length of the effective electrode portion of one end of the glass tube is the same as the length of the effective electrode portion of the other end of the glass tube, whereby a high output current can be obtained compared to the prior art for the same input voltage. Can increase the efficiency.

Fluorescent lamp, external electrode

Description

Fluorescent lamp and its manufacturing method {Fluorescent lamp and method of fabricating the same}

1 is a view for explaining the principle of operation of a conventional external electrode fluorescent lamp.

2 is a view showing a conventional external electrode fluorescent lamp.

3A and 3B illustrate a method of manufacturing an external electrode fluorescent lamp according to the present invention.

4A to 4F are steps for explaining a step of manufacturing an external electrode fluorescent lamp according to the present invention;

5 is a view showing one end of the external electrode fluorescent lamp according to the present invention.

6 is a diagram illustrating input voltage versus current according to the length of an external electrode.

* Description of the symbols for the main parts of the drawings *

400: glass tube 410, 412: other end

420, 422: Once 430: Phosphor

440: getter 450: external electrode

The present invention relates to a fluorescent lamp, and more particularly to a fluorescent lamp formed so that the length of the electrode portion inside the both ends of the fluorescent lamp and the manufacturing method thereof.

In general, flat panel displays are classified into a light emitting type and a light receiving type, and the light emitting type includes a cathode ray, an electroluminescent (EL) element, a plasma display panel (PDP), and the like. The light-receiving type includes a liquid crystal display (LCD).

The light-receiving display device itself emits light and does not form an image, but receives light from the outside to form an image, so that a separate light source, for example, a backlight is installed to observe the image in a dark place.

Fluorescent lamps used in the backlight include cold cathode fluorescent lamps (CCFLs) in which both electrodes are installed in the tube, and external electrode fluorescent lamps (EEFL) in which both electrodes are installed outside the tube.

CCFLs are classified into an edge type method using a light guide plate and a direct type method arranged in a plane according to the arrangement of the light source with respect to the display surface.

The edge type CCFL itself emits high brightness, but the panel's brightness is low, making it unsuitable for large screen panels. In addition, the direct type cannot be driven by a single inverter by connecting the CCFLs in parallel, and because the arrangement interval between CCFLs is large by limiting the number of CCFLs arranged in a plane for proper brightness of the panel, a special structure reflecting plate is required. Since the distance between the diffusion plate and the lamp is increased in order to obtain uniform brightness, there is a problem in that the thickness of the panel is increased.

Therefore, EEFL is required and proposed in response to the development of a backlight that can provide a long life and light weight while ensuring high brightness and high efficiency of the liquid crystal display of the larger size trend.

EEFL applies a fluorescent material to the inner wall of the glass tube, injects a gas mixed with mercury (Hg), neon (Ne) and argon (Ar) into the glass tube, seals both ends of the glass tube, and forms a conductor film on both ends of the glass tube. Manufacture.

1 is a view illustrating a principle of operation of a general external electrode fluorescent lamp.

Referring to FIG. 1, a high voltage (about 1,400 to 1,500 V) and 55 to 60 kHz power supplied by the inverter 130 to external electrodes 110 installed at both ends of the glass tube 100 filled with the discharge gas 120. When the emitted electrons hit the vaporized mercury particles inside the glass tube 100, the ultraviolet rays collide with the fluorescent material to emit visible light. Unlike the fluorescent lamps, the electrodes are exposed to the outside and emit electrons by an electric field. It is lighted in a manner and a large amount of lamps can be lit with one inverter 130. In addition, it has a lifespan of 20,000 to 50,000 hours, a diameter of 10 mm or less, low power consumption, and no heat generation.

When a voltage is applied to the external electrodes 110 at both ends of the glass tube 100, plasma is formed in the discharge tube, and ions and electrons are respectively accumulated as wall charges on the inner wall of the glass tube 100 at both electrode portions. When the poles of the wall charges are changed, their wall charges move in opposite directions, so that current flows in the discharge tube, and wall charges are accumulated on both electrodes. This type of discharge is called capacitively coupled alternating current discharge.

In this way, the charged particles do not flow directly to the electrode by the dielectric layer, and the wall charges are accumulated in the dielectric layer of the electrode portion in the same manner as the dielectric barrier discharge (DBD) in the plasma display panel (PDP). .

2 illustrates a conventional external electrode fluorescent lamp.

As shown in FIG. 2, the shape of one end 220 of the glass tube is different from that of the other end 210. In general, the capacitance of the capacitor is proportional to the area of the pole plate and inversely proportional to the distance of the pole plate. Therefore, a difference occurs in the area of the electrode plate due to the difference in the length of the effective electrode portions at both ends of the glass tube. Here, the effective electrode portion refers to a portion of the external electrode which acts as a pole plate of the condenser inside the glass tube. Due to the difference in the area of the pole plate, a difference in capacitance at both ends occurs. Since the capacitance of the entire glass tube is determined by the shorter length of the effective electrode portions at both ends of the glass tube, there is a problem that the efficiency is lowered.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a fluorescent lamp and a method of manufacturing the same, wherein the effective electrode portions at both ends of the fluorescent lamp are the same.

Fluorescent lamp according to the present invention for achieving the above technical problem, the glass tube; And external electrodes formed at both ends of the outer circumferential surface of the glass tube, wherein the glass tube has a length equal to the length of the effective electrode portion at the other end of the glass tube. It features.

Fluorescent lamp according to the present invention for achieving the above technical problem, the glass tube; And external electrodes formed at both ends of the outer circumferential surface of the glass tube, wherein the glass tube is formed such that the length of the effective electrode portion inside the external electrode at one end of the glass tube is equal to the length of the effective electrode portion at the other end of the glass tube. One end of the glass tube is characterized in that the flat shape.

According to another aspect of the present invention, there is provided a method of manufacturing a fluorescent lamp, the method including: applying a phosphor to an inner surface of a glass tube having both ends opened; A baking step of removing deposits and organic matters of the applied phosphor; Forming a getter room at one end of the glass tube; Sealing the other end of the glass tube; Evacuating the glass tube and injecting a discharge gas; Thread cutting one end of the glass tube; And forming one end of the glass tube such that the length of the effective electrode portion of one end of the glass tube is the same as the length of the effective electrode portion of the other end.

The method of manufacturing the fluorescent lamp further includes forming external electrodes at both ends of the glass tube and aging.

The molding may include heating one end of the glass tube; Shaping one end of the glass tube into a flat pressed shape such that the length of the effective electrode portion inside the outer electrode of one end of the glass tube is equal to the length of the effective electrode portion of the other end; And annealing one end of the glass tube to remove the stress of the glass tube.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. For each figure, like reference numerals denote like elements.

3A and 3B are flowcharts illustrating a method of manufacturing an external electrode fluorescent lamp according to the present invention, and FIGS. 4A to 4F are steps for explaining a step of manufacturing the external electrode fluorescent lamp according to the present invention.

3A, 3B, and 4A to 4F, a glass tube (bulb) is introduced into the fluorescent lamp manufacturing apparatus (step S300). As shown in FIG. 4A, the glass tube 400 is open at both ends 410 and 420.

The first yttrium film is coated on the inner surface of the glass tube and the glass tube is dried (step S305). This is to protect the dielectric with weak durability from discharge so that the fluorescent lamp can operate stably for a long time and lower the discharge voltage by emitting a lot of secondary electrons during discharge.

The phosphor is coated on the inner surface of the glass tube and the glass tube is dried (S310). This is because ultraviolet light generated by the discharge is converted into visible light while passing through the phosphor film. As shown in FIG. 4B, the fluorescent layer 430 is formed inside the glass tube 400.

After drying, the other end inner surface of the glass tube is cleaned, and a second yttrium oxide film is coated on the other end inner surface of the glass tube, and the glass tube is dried (step S315). After drying, the inner surface of the glass tube is cleaned with a metal brush to seal the other end of the glass tube.

Baking the glass tube (S320 step). In the baking process, the organic binder inside the glass tube is removed and the baking process is performed at a high temperature to prevent the phosphor from falling off from the glass tube by the binder.

In addition, by supplying hot air to prevent the impurity gas generated during the baking process inside the glass tube to be adsorbed to the phosphor and to smooth debinding.

A getter room is formed at one end of the glass tube (step S325). When forming the getter room, it is temporally sealed for later processing. The other end of the glass tube is sealed (step S330).

As shown in FIG. 4C, a getter room is formed at one end 420 of the glass tube to accommodate the getter 440, one end 422 of the glass tube is sealed, and the other end 412 of the glass tube is sealed. have.

The mercury getter is supplied to one end of the glass tube and heated and exhausted (step S335). The cleaning gas is injected through one end of the glass tube during the heating and cleaning to inject the discharge gas (step S340). Gas cleaning is to remove impurities in the glass tube.

Tip off sealing the end of one end of the glass tube (step S345). The high frequency device is used to diffuse mercury into the glass tube (S350).

After mercury diffusion is completed, one end of the glass tube is cut (step S355). The seal cutting process consists of moving the glass tube to the process position, fixing the glass tube, adjusting the length of the glass tube, and pulling the end of one end of the glass tube while heating one end of the glass tube. As shown in FIG. 4D, one end 422 of the glass tube is thread cut.

One end of the glass tube is molded so that the length of the effective electrode portion of one end of the glass tube is the same as the length of the effective electrode portion of the other end (step S360). When one end of the glass tube is pressed, one end 422 of the glass tube is heated to prevent the glass tube from breaking.

As shown in FIG. 4E, one end 422 of the glass tube is molded. One end of the glass tube is molded so that one end of the glass tube is pressed flat using an apparatus having a flat end (not shown). After forming one end of the glass tube, the one end of the glass tube is annealed to remove the stress of the glass tube.

Figure 5 shows one end of the external electrode fluorescent lamp manufactured in accordance with the present invention. Compared with the conventional external electrode fluorescent lamp shown in Fig. 2, one end is molded to have a flattened shape. Therefore, when the external electrode is formed at both ends, the effective electrode portion inside the external electrode has the same length.

Since the effective electrode portion acts as a condenser, if the length of the effective electrode portion is the same, the area of the electrode plate is the same, and the capacitances of the capacitors at both ends are the same, thereby improving the efficiency of the fluorescent lamp.

The scattering is performed by heating to a constant temperature in the diffusion oven (step S365). This is to uniformly diffuse the mercury in the glass tube.

An external electrode having a predetermined size is formed on both outside of the glass tube (S370). As shown in FIG. 4F, external electrodes 450 are formed at both ends 412 and 422 of the glass tube, respectively. In order to stabilize the characteristics of the fluorescent lamp thus produced, an aging process is performed (step S375).

6 shows the input voltage versus the output current of the lamp according to the length of the external electrode. The fluorescent lamp used in this experiment is a borosilicate glass tube with an outer diameter of 2.6mm, a thickness of 0.3mm and a length of 355mm. The discharge gas is a mixture of 97% neon and 3% argon at 80 Torr. l is the length of the external electrode (in cm).

As the current was measured while increasing the voltage from 1.0kv to 2.0kv for the input voltage of the external electrode length l = 1, 2, 3, 4, 5 (cm), the longer the electrode length, the current value for the same input voltage You can see this coming out greatly.

When one end of the glass tube has a flat molded shape according to an embodiment of the present invention, it can be seen that the length of the effective electrode inside the glass tube is longer than that of the glass tube that is not formed for the same external electrode. Therefore, the efficiency of the fluorescent lamp can be increased for the same input voltage.

Although a preferred embodiment of the present invention has been described in detail above, those skilled in the art to which the present invention pertains can make various changes without departing from the spirit and scope of the invention as defined in the appended claims. It will be appreciated that modifications or variations may be made. Accordingly, modifications to future embodiments of the present invention will not depart from the technology of the present invention.

According to the present invention, one end of the glass tube is molded such that the length of the effective electrode portion inside the outer electrode of one end of the glass tube is the same as the length of the effective electrode portion of the other end of the glass tube, so that the same input voltage is higher than that in the prior art. The output current can be obtained to increase the efficiency.

Claims (5)

delete Glass tubes; And In the fluorescent lamp comprising an external electrode formed on both ends of the outer peripheral surface of the glass tube, The glass tube, A fluorescent lamp characterized in that one end of the glass tube is formed flat so that the length of the effective electrode portion, which is a portion acting as a condenser pole plate inside the outer electrode of one end of the glass tube, is equal to the length of the effective electrode portion of the other end of the glass tube. . Applying a phosphor to an inner surface of the glass tube whose both ends are opened; A baking step of removing deposits and organic matters of the applied phosphor; Forming a getter room at one end of the glass tube; Sealing the other end of the glass tube; Evacuating the glass tube and injecting a discharge gas; Thread cutting one end of the glass tube; And And forming one end of the glass tube so that the length of the effective electrode portion serving as the condenser pole plate of one end of the glass tube is equal to the length of the effective electrode portion of the other end. The method of claim 3, Forming an external electrode on both ends of the glass tube, and further comprising the step of aging a fluorescent lamp. The method of claim 3, wherein the forming step, Heating one end of the glass tube; Molding one end of the glass tube into a flat shape such that the length of the effective electrode portion, which is a portion serving as a condenser pole plate inside the outer electrode of one end of the glass tube, is equal to the length of the effective electrode portion of the other end; And Annealing one end of the glass tube to remove the stress of the glass tube.

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